<template>
  <div class="helper">
      <span class="left">{{unCompletedCount}} items left</span>
      <span class="tabs">
          <span
            v-for="state in states"
            :key="state"
            :class="[state,  filter === state?'actived':'']"
            @click="toggleFilter(state)"
          >
              {{state}}
          </span>
      </span>
      <span class="clear" @click="clearAllCompleted">Clear completed</span>
  </div>
</template>

<script>
export default {
  props: {
      filter: {
          type:String,
          required:true
      },
      todos:{
          type:Array,
          required:true
      }
  },
  
  data(){
      return {
          states: ['all','active','completed']
      }
  },
  computed: {
      unCompletedCount(){
          return this.todos.filter(todo => !todo.completed).length
      }
  },
  methods: {
      toggleFilter(state){
          this.$emit('toggle',state)
      },
      clearAllCompleted(){
          this.$emit('clearAllCompleted')
      }
  }
}
</script>

<style lang="stylus" scoped>
.helper{
    font-weight 100
    display flex
    justify-content space-between
    padding 5px 0
    line-height 30px
    background-color #ffffff
    font-size 14px
    font-smoothing:antialiased;
}
.left,.clear,.tabs{
    padding 0px 10px
    box-sizing border-box
}
.left,.clear{
    width 150px
}
.left{
    text-align left 
}
.clear {
    text-align:right
    cursor pointer
}
.tabs{
    width 200px
    display flex
    justify-content space-around
    *{
        display inline-block
        padding 0px 10px
        cursor pointer
        border 1px solid rgba(175,47,47,0)
        &.actived{
            border-color rgba(175,47,47,0.4) 
            border-radius 5px
        }
    }
}
</style>